Video Switching Matrix

In one of my earliest posts, I outlined my pre-wire, which consisted mainly of Cat6 cabling, some RG6QS (Coax) for Satellite receivers, and audio for a distributed audio system. There was no pre-wired video distribution system as HDMI was impractical for long runs and likely way too expensive to wire everywhere anyway. Technology has changed that a bit.

When we first moved in, I set up a distributed audio system that could play any one of 6 sources plugged into it into any of 8 zones (rooms). This is really nice and lets you walk around the house listening to music or whatever and also lets me listen so something in one room, while somebody else can listen to one of the other sources in another room. It's really quite nice. For TVs though, we had a much simpler setup, with local sources hooked up directly to each of our TVs. Each TV had a DirecTV receiver, but some had a BluRay player or an AppleTV, depending on where it was and what we watched there.


As we moved through time, this got a bit more complex. Our family got a bit larger, and I added some additional TVs in places like my office, which meant more DirecTV receivers (each with a monthly fee) or whatever source we thought we'd watch on them. The way we watched TV changed a bit too. We used to watch things like the local news or other 'regular' TV in the living room. We have the nice media room we would use to watch movies in the evenings or sporting events. But as the kids get older, we find they might want to watch a movie, and I don't want them in the media room where we can't keep an eye on them, so we'd want them to watch in the playroom, or living room. Or they'd be playing in the playroom and I'd want to watch some sporting event on that TV while I kept an eye on them, or we'd want to watch some show on Netflix in bed or whatever, but it seemed ultimately we didn't always have the right sources in the right places. So either we'd not be able to watch what we want, or I'd be unhooking a BluRay player to go hook it up in the living room for the kids or something like that. At this point, I started to consider a distributed video solution much like our distributed audio system.

Eight inputs and eight outputs.
Eight inputs and eight outputs.

In the meantime, some technology change has made a distributed video system into a much easier thing to setup (although not THAT easy). Distributing video has always had the difficulty of getting an HDMI signal around the house. Pulling long HDMI cables is difficult, and there is also the issue of controlling all of the devices at the head end, from the various rooms, which means that you not only have to distribute video from the head end around the house, but also collect IR signals from around the house back to the head end. Even with the extensive pre-wire I did, it wasn't going to be sufficient enough to do that. However, a few years ago a technology called HDBaseT was invented, and has now sufficiently matured. HDBaseT basically consists of a transmitter and receiver that connect over a single Cat6 cable to carry HDMI. Not only does it carry full HDMI, but the technology can also carry an additional audio channel, as well as RS-232 and Bi-Directional IR (not only IR from the source to the display, but also from the display to the source). THIS is the answer to distributed video! Now you can plug in a transmitter in the head end, and plug in a receiver at your TV which will not only carry the video to the TV, but also carry IR signals from the TV back up to the head end. All you need is a transmitter/receiver pair for each TV, and a switching matrix at the head end and you can put one of each type of source in one place and have them all accessible everywhere.


Of course, this is an obvious use of the technology and so many manufacturers offer a combination matrix switch HDBaseT transmitter, where each output is an HDBaseT transmitter, so you only need to get HDBaseT receivers to place at each TV. So after much research, I decided to go down this route. The biggest issue I faced was cost which really keeps these things from being a practical solution at all. Ultimately, I was only able to go ahead once I found a quite frankly ridiculous deal on an 8X8 HDBaseT matrix and even then it's still nowhere near the most cost effective approach and I had to justify it based on the features and convenience.


So I promptly returned almost all of my DirecTV receivers, and set up the rest of the sources in the media room equipment rack. Plugged into the matrix I now have: DirecTV DVR, DirecTV Receiver, BluRay Player, XBox360 and two AppleTVs (A 3rd Gen and a 4th Gen. I originally bought the 4th Gen to replace the 3rd Gen, but thought I might as well hook them both up - turns out we use them both at the same time sometimes). At each TV, I have a small receiver box that basically plugs into the Cat6 at that location, and then has an HDMI out that goes to the TV and an IR in that carries remote signals back up to the head-end. It works very well. The latency is very low. It's important to note that HDBaseT is really just a fancy transmission protocol - it doesn't process the signal in any way - so it introduces little if any lag. Playing video games on any TV in the house is not an issue (not from an HDBaseT point of view at least. The only real limiter is controller range for the XBox360 controls).


There are a lot of conveniences to a setup like this. The most obvious is that I don't have to buy 4 BluRay players, but I can watch BluRay on any TV in the house. That goes for all of my sources. Also, things I hadn't thought of like if the kids are watching a movie upstairs and I want to know how much is left, or what's going on, I can just turn the TV I'm watching to that source and check. Also, much like DirecTV's ads, I can pause whatever I'm watching (Not just DirecTV) go into another room, and finish watching it there. Nice to finish a movie in bed or something. Another nice plus is that if I add another TV anywhere in the house, I only need to buy an HDBaseT receiver, and then that TV instantly gets all 6 sources I have setup (or if I buy some new kind of source device, I get it on all TVs in the house right away). One other note, is that since the matrix is located in the same rack as the whole house audio system, I ran one zone's output audio into one of the audio system's inputs. So now I can basically choose any video source and it's available as an audio stream in any of the house's audio zones. An example of what this would be used for would be say, to listen to the audio of a baseball game while in the back yard.


At the end of the day, it's still not exactly a no-brainer. Besides the cost there is a bit of a setup issue.  Usually when you connect a source to an HDMI display, they exchange some data called EDID which basically consists of the display telling the source what it's capabilities are (resolution, supported audio formats, etc...) so that the source can send the correct type of signal. When you introduce a matrix switch into the mix this can be an issue. The matrix switch kind of solves this by using a lowest-common-denominator type of method to ensure everything can play on every source. All of my TVs can play 1080p, and all the sources can output that resolution, so that hasn't been too much of an issue, but there were a couple of hiccups around audio formats. I've got the problems solved now, but it can be an issue.



The switch also has a serial port, and like the whole house audio system, and the pool controller, I wrote a simple plugin so that my automation system can talk to it as well.

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